Infrared radiation absorbing articles and method of manufacture

ABSTRACT

In an embodiment, a silicone coating composition, comprises a coating matrix comprising a partial condensate of a silanol of the formula R n Si(OH) 4-n , where n equals 1 or 2, and wherein R is selected from a C 1-3  alkyl radical, a vinyl radical, a 3,3,3-trifluoropropyl radical, a gamma-glycidoxypropyl radical, and a gamma-methacryloxypropyl radical; and ITO having a mean particle size of less than or equal to 60 nm as determined by dynamic light scattering; and wherein the silicone coating composition is free of colloidal silica. In another embodiment, a coated glazing, comprises a plastic substrate; and a cured silicone coating on the substrate.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional application of Non-Provisionalapplication Ser. No. 13/681,791, filed on Nov. 20, 2012 which claimspriority to Provisional Application Ser. No. 61/604,939, filed on Feb.29, 2012, both applications of which are incorporated herein byreference in their entirety.

BACKGROUND

Disclosed herein are infrared radiation absorbing coatings, articlescomprising the coatings, and methods for making and using the same.

Use of polymeric based glazing materials in automotive applications hasraised certain problems. This is due, at least in part, to the uniquechallenges posed by automotive service conditions. While not anexhaustive list, these include: extremes of temperature andenvironmental exposure; intense and prolonged vibrational forcestransmitted through the glazing material during normal operation of theautomotive vehicle; occasional instances of intense shock and impactloads which may be randomly exerted on the glazing material; scratchingof the surface by incidental contacts such as in washing of the vehicleor the impacting of dust and other particles; and routine thoughprolonged exposure to debilitating environmental factors such as rainand the ultraviolet and infrared radiation in sunlight.

Another problem encountered in the use of polymeric based glazingmaterials (e.g., polycarbonate) in automotive glazing applications isthe need to reduce penetration of solar infrared radiation through thewindows into the automobile interior, creating undesirable heat loads,particularly during summer months. While a similar problem has beenencountered with silica based glass compositions in automotive glazingapplications, the heat load problem can be addressed with the use ofinorganic glass coatings or additives which can be integrated duringglass formation or in suitable post formation steps. Heretofore, methodsand strategies for reducing the heat load potential for polycarbonatebased glazing compositions suitable for use in automotive applicationshas been more problematic. Some issues encountered includeincompatibility of materials, conflicting properties, and so forth.

What is needed in the art is a plastic article that is transparent,infrared radiation absorbent, abrasion resistant, and has low haze.

BRIEF DESCRIPTION

Disclosed herein are silicone hard coats comprising indium-doped tinoxide (ITO), articles comprising the silicone hard coat, and methods formaking the same.

In an embodiment, a method for making an infrared radiation absorbingcoating comprises: forming an ITO coating mixture comprising ITO and afirst coating matrix, wherein the first coating matrix comprises thepartial condensate of a silanol of the formula R_(n)Si(OH)_(4-n), wheren equals 1 or 2, and wherein R is selected from a C₁₋₃ alkyl radical, avinyl radical, a 3,3,3-trifluoropropyl radical, a gamma-glycidoxypropylradical, and a gamma-methacryloxypropyl radical, wherein the ITO coatingmixture is free of colloidal silica; forming a colloidal silica coatingmixture comprising colloidal silica and a second coating matrix, whereinthe second coating matrix comprises the partial condensate of a silanolof the formula R_(n)Si(OH)_(4-n), where n equals 1 or 2, and wherein Ris selected from an alkyl radical of 1 to 3 inclusive carbon atoms, avinyl radical, a 3,3,3-trifluoropropyl radical, a gamma-glycidoxypropylradical, and a gamma-methacryloxypropyl radical; and mixing the ITOcoating mixture with the colloidal silica coating mixture to form acombined mixture. The combined mixture does not comprise a precipitatevisible to the unaided eye after 2 weeks without stiffing.

In an embodiment, a silicone coating composition comprises: a coatingmatrix, comprising the partial condensate of a silanol of the formulaR_(n)Si(OH)_(4-n), where n equals 1 or 2, and wherein R is selected froma C₁₋₃ alkyl radical, a vinyl radical, a 3,3,3-trifluoropropyl radical,a gamma-glycidoxypropyl radical, and a gamma-methacryloxypropyl radical;colloidal silica; and ITO having a mean particle size of less than orequal to 60 nm as determined by dynamic light scattering.

In another embodiment, a silicone coating composition comprises: acoating matrix comprising the partial condensate of a silanol of theformula R_(n)Si(OH)_(4-n), where n equals 1 or 2, and wherein R isselected from a C₁₋₃ alkyl radical, a vinyl radical, a3,3,3-trifluoropropyl radical, a gamma-glycidoxypropyl radical, and agamma-methacryloxypropyl radical; ITO having a mean particle size ofless than or equal to 60 nanometers (nm) as determined by dynamic lightscattering; and wherein the silicone coating is free of colloidalsilica.

The above described and other features are exemplified by the followingdetailed description.

DETAILED DESCRIPTION

It is desirable to provide an article (e.g., a glazing article), e.g.,for automotive or architectural application, with a specified balancebetween visible light transmittance “Tvis” (higher is generally better)and total solar transmittance “Tts” (lower is generally better). For agiven Tts, higher Tvis can extend the glazing color range, therebyaffording greater design flexibility. For a given Tvis, lower Tts canlower air conditioning demand on hot sunny days, which can improve fueleconomy or electric range. However, these characteristics, Tts and Tvis,tend to be in conflict. More specifically, it is desirable to achieve abalance of Tvis and Tts for plastic-based glazing, while meetingapplication-dependent requirements for uniformity of appearance andoptical function, haze (i.e., forward light scattering),abrasion-resistance, color, and weatherability, within applicablemanufacture-related limitations (e.g., on additive concentration inplastic resin).

Specifically, it is desirable to provide an article that maintains theproperties of current articles, yet further has infrared (“IR”)absorbance properties. Plastic materials often do not have adequateabrasion resistance for automotive or glazing applications. Typically,they are coated with weatherable, abrasion resistant coatings.Particularly desirable coatings are silicon hard coats comprisingcondensed silanols, colloidal silica, and ultraviolet (UV) absorbers.Examples include AS4000, AS4010, and AS4700 available commercially fromMomentive Performance Materials. Due to the incompatibility of ITO withcolloidal silica as well as the color that many IR absorbers impart tothe composition, the particular IR absorbers that can be employed in asilicone hard coat have been very limited. Hence, for example, the useof metal oxide nano-particles, particularly ITO, has been very limited.Where the use of ITO has been attempted, the optical clarity and thermalstability of the article was unacceptably reduced (for example, seeEP2009057 B1 to Nakae).

Disclosed herein are glazing articles comprising the following elements:a substrate (also referred to as a glazing), IR absorbent coating(s) oneither or both sides of the substrate, and optional layer(s) (e.g.,weatherable coatings, primers, and so forth). As used herein, layerincludes film (free standing before attaching to the article), andcoating (created on the article). Disposed in one or more locations(e.g., same or different: coating(s), film(s), and/or substrate) in thearticle can be two or more different additives with respective spectralproperties that are complementary to attain a desired resultanttransmission spectrum (e.g., with respect to visible light transmittanceand total solar transmittance). The additives can be strategicallyplaced in the glazing article relative to the component in which theglazing article will be employed (e.g., a vehicle or building interioror exterior), and/or relative to other functional elements, such as UVabsorbing and/or abrasion-resistant coatings.

Some additives discernibly affect color of the host (substrate, filmand/or coating(s)); others do not. In cases where the coatingapplication method (e.g., flow or dip coating) tends to produce agradient in coating thickness, it is preferable to locate the coloraffecting additives in the substrate or film (if used) or in an in-moldcoating (e.g., commonly assigned U.S. Patent Publication No.2008/0265459) or in a coating deposited under vacuum, so as to provide auniform distribution, and hence a uniform function and appearance.Additives that do not discernibly affect color (at practicalconcentrations) can be located in coating(s) with thickness gradientswithout generating non-uniform appearance, provided functionalrequirements are met over the range of coating thickness. In addition toproviding appropriate spectral properties, the additives are soluble orform stable dispersions in the respective hosts, do not impartunacceptable haze, and are stable both during manufacturing (e.g., UV orthermal curing of coatings) and in service.

The substrate can comprise plastic (e.g., a transparent plastic) such aspolycarbonate resin, acrylic polymers, polyacrylate, polyester,polysulfone resins, as well as combinations comprising at least one ofthe foregoing. The polycarbonate resins can be aromatic carbonatepolymers which may be prepared by reacting dihydric phenol(s) with acarbonate precursor such as phosgene, a haloformate, or a carbonateester. One example of a polycarbonate which can be used is LEXAN*polycarbonate, commercially available from SABIC Innovative Plastics,Pittsfield, Mass.

Acrylic polymers can be prepared from monomers such as methyl acrylate,acrylic acid, methacrylic acid, methyl methacrylate, butyl methacrylate,cyclohexyl methacrylate, and the like, as well as combinationscomprising at least one of the foregoing. Substituted acrylates andmethacrylates, such as hydroxyethyl acrylate, hydroxybutyl acrylate,2-ethylhexylacrylate, and n-butylacrylate can also be used.

Polyesters can be prepared, for example, by the polyesterification oforganic polycarboxylic acids (e.g., phthalic acid, hexahydrophthalicacid, adipic acid, maleic acid, terephthalic acid, isophthalic acid,sebacic acid, dodecanedioic acid, and so forth) or their anhydrides withorganic polyols containing primary or secondary hydroxyl groups (e.g.,ethylene glycol, trimethylene glycol, butylene glycol, neopentyl glycol,and cyclohexanedimethanol).

Polyurethanes are another class of materials which can be used to formthe substrate. Polyurethanes can be prepared by the reaction of apolyisocyanate, with a polyol, polyamine, or water. Examples ofpolyisocyanates include hexamethylene diisocyanate, toluenediisocyanate, diphenylmethane diisocyanate (MDI), isophoronediisocyanate, and biurets and thiocyanurates of these diisocyanates.Examples of polyols include low molecular weight aliphatic polyols,polyester polyols, polyether polyols, fatty alcohols, and the like.

Examples of other materials from which the substrate may be formedinclude acrylonitrile-butadiene-styrene polymers, VALOX*(polybutylenephthalate, commercially available from SABIC InnovativePlastics), XENOY* (a blend of LEXAN* and VALOX*, commercially availablefrom SABIC Innovative Plastics), and the like. Also included arecombinations with any of the above substrate materials.

The substrate can be formed in various manners such as by injectionmolding, extrusion, cold forming, vacuum forming, blow molding,compression molding, transfer molding, thermal forming, and so forth.The article may be in any shape and need not be a finished article ofcommerce, that is, it may be sheet material or film which would be cutor sized or mechanically shaped into a finished article.

The transparent plastic substrate may include bisphenol-A polycarbonateand other resin grades (such as branched or substituted) as well asbeing copolymerized or blended with other polymers such as polybutyleneterephthalate (PBT), poly-(acrylonitrile-butadiene-styrene) (ABS),polyarylates, or polyethylene.

The transparent plastic substrate can further comprise variousadditive(s), such as colorant(s), mold release agent(s), antioxidant(s),surfactant(s), plasticizer(s), IR absorber(s), antistat(s),antibacterial(s), flow additive(s), dispersant(s), compatibilizer(s), UVabsorber(s), and a combination comprising at least one of the foregoingadditives.

Weathering layer(s) can optionally be applied to one or both sides ofthe substrate. The layer can have, for example, a thickness of less thanor equal to 100 micrometers (um), specifically, 4 μm to 65 μm. Theweathering layer(s) can include UV absorbing material (e.g.,hydroxybenzophenone(s), hydroxyphenylbenzotriazole(s),hydroxyphenyltriazine(s), polyaroylresorcinol(s), and cyanoacrylate(s),as well as combinations comprising at least one of the foregoing). Theweathering layer(s) can be, for example, a polyurethane (e.g., apolyurethane-acrylate), acrylate, silicone-based material, fluorocarbon(e.g., polyvinylidene fluoride), acrylic material, as well ascombinations comprising at least one of the foregoing. Desirably, theweathering layer has a Taber delta haze (abrasion resistance test) ofless than 10%, specifically, less than or equal to 5%. As used herein,Taber delta haze is determined using CS-10F wheels, a 500 gram (g) load,and 500 cycles as specified by ASTM D1044-08.

The IR coating can be a silicone hard coat with metal oxidenano-particles. Such coatings can provide low haze, weatherability,UV-absorption, and abrasion-resistance. As used herein, weatherabilityrefers to no cracking (per the unaided eye with normal 20/20 vision) andno delamination (per tape test according to ASTM D3359-08), afterweatherability testing in Florida, outdoors, for a period of at least 3years, and at an angle of 5 degrees. This may be simulated by exposureto at least 9 megajoules per square meter per nanometer (MJ/m²/nm)measured at 340 nm in a xenon arc weathering device using a protocolemploying daylight filters such as described in ASTM G155-05. As usedherein, haze is determined in accordance with ASTM D1003-11, procedure Awith CIE standard illuminant C (see ISO/CIE 10526). Desirably, thecoated glazing (substrate with the IR coating), has a haze of less than5%, specifically, less than or equal to 3%, and more specifically, lessthan or equal to 1.5% and yet more specifically, less than or equal to1%.

Examples of metal oxide nano-particles include ITO, antimony-doped tinoxide (ATO), fluoride-doped tin oxide (FTO), gallium-doped zinc oxide(GZO), aluminum-doped zinc oxide (AZO), indium-doped zinc oxide (IZO),and combinations comprising at least one of the foregoing. Desirably,the metal oxide nano-particles have a mean particle size of less than orequal to 60 nm, specifically, less than or equal to 45 nm, morespecifically, less than or equal to 40 nm, and more specifically, 10 nmto 30 nm, as determined by dynamic light scattering (DLS). Specifically,greater than or equal to 90% of particles can have diameters of lessthan 61 nm, more specifically, greater than or equal to 95% can havediameters of less than or equal to 71 nm. Agglomeration ofnano-particles with each other can be inhibited by suspending metaloxide nano-particles in solvent before addition to a coating matrix; bysuitable nano-particle surface modification; and/or by observingconcentration limits

ITO has proven particularly useful for IR absorption, but has previouslynot been readily employed while maintaining weatherability and abrasionresistance (e.g., Taber delta haze). ITO is generally purchased in theform of a dispersion. When the ITO dispersion is combined with acolloidal silica coating mixture (i.e., a coating mixture comprisingpartially condensed silanols and colloidal silica), agglomeration(manifested as precipitation and/or high turbidity) occurs. The severityof the agglomeration is such that it is visible to the unaided eye. Inother words, when an ITO dispersion is combined with a colloidal silicacoating mixture, precipitation occurs in less than or equal to one week.As used herein, unless specified otherwise, visible refers to visible tothe unaided eye. As used herein, unaided eye refers to normal 20/20vision.

In one embodiment, di and/or trialkoxy silanes (without colloidalsilica), and optionally including additive(s) and the like, are mixedwith ITO (also referred to herein as an ITO dispersion which is ITO asreceived from the supplier) to form an ITO coating mixture. The ITO isreceived as a dispersion for ease of handling, e.g., dispersed in asolvent such as water, an alcohol (e.g., isopropyl alcohol (IPA)), or acombination comprising at least one of the foregoing. For example, ITOcan be purchased commercially from Shanghai Huzhen Nano Technology Co.Ltd., under the product code ITO-MP030 comprising 30 weight percent (wt%) ITO and 70 wt % isopropyl alcohol. The ITO coating mixture can beapplied to the substrate to attain the desired IR protection. Sincecolloidal silica is not present in this embodiment, the advantages(e.g., abrasion resistance) attained therewith are also not present.

A silicone coating matrix can comprise a lower aliphatic alcohol-watermixture of the partial condensate of silanol(s) of the formulaR_(n)Si(OH)_(4-n), where n equals 1 or 2 and R is selected from alkylradicals of 1 to 3 inclusive carbon atoms, a vinyl radical, a3,3,3-trifluoropropyl radical, a gamma-glycidoxypropyl radical, and agamma-methacryloxypropyl radical. Optionally, greater than or equal to70 wt % of the silanol can be CH₃Si(OH)₃. When a mixture is made withthe silicone coating matrix, the mixture can comprise colloidal silicaor ITO, and can comprise 10 to 50 wt % solids including 10 to 90 wt % ofthe partial condensate. Optionally, the mixture can comprise sufficientacid to have a pH of 3.0 to 6.0.

A colloidal silica coating mixture comprises a colloidal silicadispersion and the silicone coating matrix. The colloidal silica coatingmixture can contain 10 to 50 wt % solids with the solids comprising 10to 80 wt % colloidal silica and 20 to 90 wt % of the partial condensate,and optionally sufficient acid to provide a pH of 3.0 to 6.0. Examplesof colloidal silica coating mixtures are disclosed in U.S. Pat. No.3,986,997 to Clark. Further examples of colloidal silica coatingmixtures include such silicone resin coating solutions such as AS4010 orAS4700 (commercially available from Momentive Performance Materials).There can be additives introduced before or after the colloidal silicadispersion is combined with the silicone coating matrix.

An ITO coating mixture comprises an ITO dispersion and the siliconecoating matrix. The ITO coating mixture can contain 10 to 50 wt % solidswith the solids comprising 10 to 70 wt % ITO and 30 to 90 wt % of thepartial condensate, and optionally sufficient acid to provide a pH of3.0 to 6.0. There can be additives introduced before or after the ITOdispersion is combined with the silicone coating matrix. The ITOnano-particles can be incorporated into the silicone coating matrix viasuitable processing steps and under suitable processing conditions toproduce an ITO coating mixture, for example, by stirring for greaterthan or equal to 24 hours.

As noted above, when the ITO is directly combined with a colloidalsilica coating mixture, agglomeration of ITO nano-particles withcolloidal silica, generally occurs (e.g., without the addition ofpolymeric dispersant). It has been discovered, however, that theincompatibility between ITO and colloidal silica can be overcome, i.e.,it is now possible for ITO and colloidal silica to co-exist in a commoncoating mixture without agglomeration of the ITO nano-particles, e.g.,without visible turbidity or precipitation for a period of two weeks,and even for more than two weeks. This compatibility can be attainedeven without adding a polymeric dispersant (e.g.,polymethylmethacrylate) to the ITO dispersion received from thesupplier. In other words, the ITO coating mixture can comprise less thanor equal to 0.05 parts by mass polymeric dispersant with respect to 1part by mass ITO, specifically, less than or equal to 0.01 parts by masspolymeric dispersant with respect to 1 part by mass ITO, and morespecifically, 0 parts by mass polymeric dispersant. It was discoveredthat ITO and colloidal silica can be introduced respectively intoseparately prepared silicone coating matrices which, after the resultingcoating mixtures are individually aged, can be combined to form acombined mixture comprising the coating matrices, ITO, colloidal silica,and any optional additive(s). In other words, the combined mixture canhave an amount of polymeric dispersant such that if the ITO (e.g., ITOdispersion) were mixed directly with the colloidal silica coatingmixture to form a sample mixture having the same amount of polymericdispersant as the combined mixture, precipitation occurs in the samplemixture in less than or equal to one week with no agitation.

One separately prepared mixture, the ITO coating mixture, contains asilicone coating matrix, ITO, no colloidal silica (e.g., 0 wt %colloidal silica based upon a total weight of the ITO coating mixture),and optionally further contains cure catalyst(s), UV absorber(s), andoptionally other additive(s). Another mixture, the colloidal silicacoating mixture, contains a silicone coating matrix, colloidal silica,no ITO (e.g., 0 wt % ITO based upon a total weight of the colloidalsilica coating mixture), and optionally further contains curecatalyst(s), UV absorber(s), and optionally other additive(s). Eachmixture, the ITO coating mixture and the colloidal silica coatingmixture can be aged prior to forming the single mixture, i.e., thecombined mixture. The aging time is dependent upon the exactformulation, with sufficient time and agitation such that a combinedmixture (the combination of the ITO coating mixture and the colloidalsilica coating mixture) is obtained which exhibits no visibleprecipitation (to the unaided eye) for at least two weeks withoutagitation. Aging can be achieved by agitation (e.g., stirring at roomtemperature) for greater than or equal to 1 day (e.g., 1 day to 2 weeks)or by warming to 35 degrees Celcius (° C.) to 65° C. and agitating(e.g., stiffing) for greater than or equal to an hour (e.g., for onehour to one day).

Possible additives that can be employed with the coating mixture(s)include colorants, antioxidants, surfactants, plasticizers, IR absorbers(e.g., in addition to the ITO), antistats, antibacterials, flowadditives, dispersants, compatibilizers, cure catalysts, UV absorbers,and a combination comprising at least one of the foregoing additives.

Once the ITO coating mixture has been aged, then, the combined mixturecan be formed by combining (e.g., blending) the separately prepared ITOcoating mixture and colloidal silica coating mixture. Desirably, thecombined mixture is formed once the ITO coating mixture and colloidalsilica coating mixture have been aged. As is noted above, one or both ofthe separately prepared mixtures (i.e., the ITO coating mixture and/orthe colloidal silica coating mixture) can contain UV absorbers, curecatalyst, as well as other additive(s) as desired. UV absorber(s), curecatalyst(s), and other optional additive(s) also can be added to thecombined mixture at the time of mixing or later as desired.

In various embodiments, the colloidal silica coating mixture (withcolloidal silica and without ITO) could be a silicone hard coat mixturesuch as AS4010 or AS4700 (commercially available from MomentivePerformance Materials). The coating matrix to be mixed with the ITO canbe the same composition as the coating matrix for the colloidal silicamixture (e.g., the same as AS4010 or AS4700 without the colloidalsilica). This allows the use of the same UV absorber at the same loadingin the ITO coating mixture, yielding the same UV absorber loading in thecombined mixture as in the standard silicone hard coat, e.g., as iscurrently employed to attain the desired properties, with the additionalbenefit of enhanced IR absorption properties.

Alternatively, the colloidal silica coating mixture can have higher thanstandard UV absorber and/or colloidal silica loadings to compensate fordilution by the ITO coating mixture containing no colloidal silica, andoptionally no UV absorber. The combined mixture (i.e., the combined ITOand colloidal silica coating mixtures) can therefore have the same UVabsorber and colloidal silica loadings as in a conventional siliconehard coat mixture but with the addition of the ITO. In other words, theloading of each component in the coating mixtures can be determinedbased upon a desired loading of the combined mixture (comprising the ITOcoating mixture and the colloidal silica coating mixture). Furthermore,due to this method of making the combined mixture, ITO and colloidalsilica can be combined in a single mixture without adding additionalpolymeric dispersant. Besides optionally purifying the ITO dispersionand/or ITO coating mixture, the ITO dispersion can be used as purchasedfrom a supplier. In some embodiments, the combined mixture is free ofpolymeric dispersant.

The concentration of the metal oxide nano-particles, namely ITO, in thecombined mixture is based upon the desired concentration in the final,cured coating. The concentration of ITO nano-particles in the finalcured coating is partially dependent upon the particular application ofthe coated article (e.g., the allowable haze and desired transmission).Generally, 2 wt % to 40 wt % can be present, specifically, 5 wt % to 40wt %, more specifically, 5 wt % to 35 wt %, and yet more specifically, 5wt % to 20 wt % or 15 wt % to 25 wt %, based upon a total weight of thecured coating (i.e., total coating solids in the final cured coating).To meet requirements specified for luminous transmittance for Item 2glazing for motor vehicles in the American National StandardsInstitute's ANSI Z26.1-1996 specification, the concentration of metaloxide nano-particles can be 10 wt % to 40 wt %, specifically, 15 wt % to35 wt %, more specifically, 20 wt % to 30 wt %, based upon a totalweight of the cured coating (i.e., total coating solids in the finalcured coating). In an Item 3 glazing application (e.g., wherein thesubstrate properties are less constrained such that it can comprisegreater IR absorbers), however, (e.g., for a rooflite), theconcentration of metal oxide nano-particles can be 2 wt % to 25 wt %,specifically, 5 wt % to 15 wt %, based upon a total weight of the curedcoating (i.e., total coating solids in the final cured coating).

In various embodiments, the addition of the ITO nano-particles to acolloidal silica mixture unacceptably increased the initial haze ofarticles coated therewith. For example, the initial haze was greaterthan or equal to 20%. It was discovered that colloidal silica coatingmixtures comprising either ammonium-stabilized colloidal silica (e.g.,commercially available from Nalco Company; Nalco 2327) oracid-stabilized colloidal silica (e.g., commercially available fromNalco Company; Nalco 1034A) behave the same. Namely, (i) addingcolloidal silica (e.g., acid-stabilized or ammonium stabilized) to anITO/IPA dispersion leads to agglomeration; and (ii) combining an ITO/IPAdispersion with a silicone hard coat mixture containing colloidal silica(e.g., acid-stabilized or ammonium stabilized) also led toagglomeration. However, as with the ammonium-stabilized colloidal silicacontaining coating mixture, applying the method disclosed herein (i.e.,combining the ITO coating mixture with a colloidal silica coatingmixture containing Nalco 1034A after aging (about 10 hours for thelatter), provided a low haze coating, i.e., no agglomeration.

Not to be limited by theory, sometimes, the Applicants found that thepresence of ITO, or possibly impurities in the ITO, in the combinedcoating mixture led to higher Taber delta haze of the coated article ascompared with the case with no ITO. Hence, further reduction of theTaber delta haze can be accomplished with the addition of a curecatalyst in one or more of the ITO coating mixture, the colloidal silicacoating mixture, and the combined coating mixture. Quaternary ammoniumsalts of carboxylic acids can be used as cure catalysts. Specificexamples of cure catalysts include tetra-n-butylammonium acetate (TBAA),tetra-n-butylammonium formate, tetra-n-butylammonium benzoate,tetra-n-butylammonium-2-ethylhexanoate,tetra-n-butylammonium-p-ethylbenzoate, and tetra-n-butylammoniumpropionate. The amount of cure catalyst can be less than or equal to 2wt %, specifically, 0.01 wt % to 2 wt %, more specifically, 0.05 wt % to1.5 wt %, still more specifically, 0.1 wt % to 1 wt % based upon a totalweight of solids in the total coating matrix. Further discussion ofpossible cure catalysts can be found in U.S. Pat. No. 4,863,520 toFactor et al.

These IR absorbing coatings can be employed on IR absorbing articlesindependently or with additive(s). In the case of additive(s), thelocation of the additives (e.g., ATO and LaB₆) is not limited (e.g., inthe substrate and/or the layer(s)), with the location of thoseadditive(s) being dictated by practical considerations. For example,since a more uniform additive loading can sometimes be attained in thesubstrate than in a coating (e.g., substrates can be molded to a uniformthickness, while coatings may have a greater variability in thicknessdepending on the coating method), the additives are generally located inthe substrate (e.g., in the polycarbonate composition). ITO is notgenerally compatible with the polycarbonate, (i.e., it cannot just beadded to the polycarbonate; for example, see EP2009057 B1 to Nakae,Paragraph [0002]). Hence the ITO is located in the coating. Therefore,the additive(s) (other than ITO), can generally be located anywhere inthe article (coating and/or substrate). For example, an organic additive(e.g., Lumogen* IR765, a commercial BASF product) and/or an inorganicadditive (e.g., LaB₆), and/or ATO, can be in a polycarbonate substrate,combined with a transparent conducting oxide (e.g., ITO (indium-dopedtin oxide), and/or ATO (antimony-doped tin oxide)) in the coating.

Optionally, one or more of the coatings can be substituted with a film(e.g., polycarbonate or polyvinyl butyral) applied to the substrate by amethod such as lamination or film insert molding. The film has spectralproperties, either naturally, by virtue of additives it contains, or byvirtue of a spectrally selective multi-layer structure carried by thefilm, that complement the spectral properties of the substrate and/orany coating(s), generally with their own respective additives. In thiscase, the coating(s) could be applied to the film and/or to the side ofthe substrate opposite the side with the film.

It is recognized that UV radiation blocking elements andabrasion-resistant elements must generally meet more stringentrequirements on the exterior side of a vehicle or building, whereas IRabsorbing coatings or films that are supplementing IR absorbingadditives in the substrate, can also be effective on the interior side.Thus for applications, such as an automotive rooflite, where a UVblocking coating might provide abrasion-resistance that is both adequateand better than that of an IR absorbing coating, the UV- and IR-coatingswould be located on the exterior and interior sides of the glazingrespectively. In other applications, where a plasma-depositedabrasion-resistant coating is applied over any other coatings, e.g.,with IR blocking function, the location(s) of the other coating(s) canbe selected without regard for its abrasion-resistance. For example, inan embodiment, a silicone hard coat comprising ITO and colloidal silicacan be located on both sides of the substrate (interior and exterior).In still another embodiment, e.g., where the system includes an IRreflecting element in addition to an IR absorbing element, whereinreflected wavelengths overlap the wavelengths absorbed by the IRabsorbing element, it is desirable that light contact the IR reflectingelement before reaching the IR absorbing element. Hence, in such asituation, the IR reflecting element can be located on the exteriorand/or be within the substrate, while the IR absorbing element can be onthe interior side, resulting in an asymmetric coating system (e.g., anasymmetric wet coating system).

The combined coating mixture (i.e., coating matrix with both ITO andcolloidal silica) can be applied symmetrically, i.e., the same coatingmixture can be applied to both sides of the substrate (e.g., glazing),while providing abrasion resistance and weatherability typical of thestandard silicone hard coats, even when there is no plasma-depositedcoating over the cured coating formed from the combined mixture. Asymmetric coating system with ITO requires no extra manufacturing stepsrelative to a symmetric coating without ITO, such as a standard siliconehard coat. The coating can be applied in various fashions such as flowcoating, dip coating, curtain coating, and so forth. The present processcan be used to form various articles, such as for automotive glazingapplications.

It is also noted that since LaB₆ is green in color, if added to acoating with a thickness gradient due to the application method (e.g.,wedge effect manifested by flow coating and certain other coatingmethods), then the resulting coating could manifest a non-uniform coloror appearance. Meanwhile, ITO nano-particles introduced into thepolycarbonate substrate would lead to high haze

The following examples are merely to further illustrate the presentcoating matrix, and coated articles, and is not intended to limit thescope hereof.

EXAMPLES Examples 1-3 Simulations

The effects of various combinations of IR absorbing materials on Tts andTvis were simulated. The absorption coefficient of each IR absorber wasmeasured separately over the wavelength range of 300 to 2,500 nm. For amixture of additives with the respective loadings (mg/cm²; based uponthe total weight of the article) in Table 1 the transmission spectrumwas determined from the Lambert-Beer law. Tvis was determined from thetransmission spectrum using Equation 1 and Table 1 of ISO 9050:2003. Thesolar direct transmittance was determined from the transmission spectrumusing Table 2 of ISO 13837:2008. The reflection spectrum was measuredfor a polycarbonate reference sample with a thickness of 4 mm and with asilicone hard coat (namely AS4010 commercially available from MomentivePerformance Materials). The solar direct reflectance was determinedusing Table 2 of ISO 13837:2008 in a manner analogous to that for solardirect transmittance, and is common to all the examples in Table 1. Ttswas determined from the solar direct transmittance and solar directreflectance using equations in Annex B of ISO 13837:2008 with windvelocity for “vehicles at rest”.

TABLE 1 Additive Loadings¹ for Minimum Tts or Maximum Tvis, FromPredictive Model Under Constraints Indicated Additive Loading (mg/cm²)Lumogen Yellow Transmission (%) Ex. Application ITO ATO LaB₆ IR 765⁴ DyeR881 T_(ts) ² (%) T_(vis) ³ (%) 1a Item 2 0 0.113 0.0474 0 0 58.82 70.001b Item 2 0.272 0 0.0470 0 0 54.36 70.00 2a Item 2 0 0.107 0.0436 0 060.00 71.05 2b Item 2 0.277 0 0.0239 0 0 60.00 75.60 3a Rooflite 0 0.2440.26 0.026 0.07 30.00 23.83 3b Rooflite 0.14 0 0.26 0.026 0.07 30.0025.72 Bolded numbers denote constrained values. ¹Additive loading is thetotal mass of an additive in the volume swept by translating a unit areaof the sample surface through the sample in the direction perpendicularto that surface. ²T_(ts) is based on ISO 13837: 2008, Convention A.³T_(vis) is based on ISO 13837: 2008, Convention A. ⁴Lumogen IR765 isquaterrylene dye (commercially available from BASF Corp.).

From Table 1 it is clear that the addition of the ITO to the articleimproved the Tts as well as the Tvis. In other words, Tts decreasedand/or Tvis increased.

Example 4 Effect on Coating Haze of Aging Period of ITO Coating Mixtureat Room Temperature with Stirring Before Combining with Colloidal SilicaCoating Mixture

A primer solution was prepared by dissolving 4.01 g of polymethylmethacrylate (PMMA) into 29.36 g of diacetone alcohol and 166.53 g of1-methoxy-2-propanol by stiffing. The primer solution was applied toboth sides of a polycarbonate substrate, allowed to evaporate at roomtemperature for 15 minutes, and baked in an oven at 125° C. for 0.5hour. The resulting haze was 0.38% as determined in accordance with ASTMD1003-11, procedure A with CIE standard illuminant C at a thickness of 3to 5 um. An ITO coating mixture was prepared by combining 6.37 gn-butanol with 9.95 g ITO dispersion (30 wt % in isopropyl alcohol). Tothis mixture 7.3 g deionized water, 0.4 g acetic acid, and 18.3 gmethyltrimethoxysilane were added with stirring. The ITO coating mixturewas aged by stiffing at room temperature (20° C.) for an aging period.The aged ITO coating mixture was combined with an equal volume of acolloidal silica coating mixture (e.g., AS4700). The combined mixturewas stirred for 30 seconds and stored at room temperature withoutfurther stirring. The combined mixture was applied to one side of thepolycarbonate substrate with the primer, allowed to stand for 15 minutesat room temperature, and cured in oven at 125° C. for 1 hour. As shownin Table 2, an aging period of the ITO coating mixture at roomtemperature with stirring should be greater than or equal to 24 hours,e.g., for the haze of the resulting cured coating to be less than 1%.Therefore, if at room temperature, it is desirable to age the ITOcoating mixture for greater than or equal to 24 hours, specifically,greater than or equal to 48 hours, and more specifically, greater thanor equal to 1 week, with agitation (e.g., stirring).

TABLE 2 Effect of Aging Period on Coating Haze (Example 4) Aging periodof ITO Haze of Coating coating solution at on PC Substrate 20° C. withstirring Mixture Appearance With Primer (%)* 4 hours Turbidity 15.8 8hours Turbidity 10.6 10 hours Clear blue solution; No turbidity 5.26 12hours Clear blue solution; No turbidity 3.41 16 hours Clear bluesolution; No turbidity 1.68 24 hours Clear blue solution; No turbidity0.98 18 days Clear blue solution; No turbidity 0.54 *ASTM D1003-11,Procedure A with CIE Standard Illuminant C Primer is on both sides of PCsubstrate; Coating is on one side Haze of PC substrate with primer was0.38% before application of coating

Examples 5-10 Effect on Coating Haze of Aging of ITO Coating Mixtureand/or Colloidal Silica Coating Mixture

polycarbonate substrates with primer were prepared as in Example 4. ITOcoating mixtures were prepared as in Example 4. Colloidal silica coatingmixtures, for Examples 7 and 9 of Table 3, were prepared in accordancewith Example 1 of U.S. Pat. No. 3,986,997 to Clark using acid-stabilizedcolloidal silica (Nalco 1034A, commercially available from NalcoCompany) as the colloidal silica coating mixture, with aging changed totwo weeks. Colloidal silica coating mixtures, for Examples 8 and 10 ofTable 3, were prepared in accordance with Example 2 of U.S. Pat. No.3,986,997 to Clark using ammonium-stabilized colloidal silica (Nalco2327, commercially available from Nalco Company) as the colloidal silicacoating mixture, with aging changed to two weeks. Mixtures were formedand coatings were applied and cured as in Example 4.

TABLE 3 Haze of Coatings From Mixture of ITO and CS Sources IndicatedMixture Haze of Ratio of Mixture Appearance - Coating on SourcesAppearance - two weeks PC Substrate Ex. ITO Source* CS Source* ITO:CSinitial after mixing with Primer (%)** 5 ITO coating CS dispersion, 2:1Precipitation Precipitation 3.69 solution, 40 wt % acid- aged stabilizedCS in water 6 ITO coating CS dispersion, 2:1 High Precipitation 51.9solution, 40 wt % turbidity aged ammonium- stabilized CS in water 7 ITOdispersion, CS coating 1:2 High Precipitation 10.2 30 wt % in solutionwith turbidity IPA acid- stabilized CS, aged 8 ITO dispersion, CScoating 1:2 High Precipitation 12.5 30 wt % in solution with turbidityIPA ammonium- stabilized CS, aged 9 ITO coating CS coating 1:1 Clearblue Clear blue 0.69 solution, solution with solution; No solution; Noaged acid- turbidity turbidity stabilized CS, aged 10 ITO coating CScoating 1:1 Clear blue Clear blue 0.78 solution, solution with solution;No solution; No aged ammonium- turbidity turbidity stabilized CS, aged*ITO coating mixtures and CS coating mixtures were aged by stirring at20° C. for two weeks **ASTM D1003-11, Procedure A with CIE StandardIlluminant C Primer is on both sides of PC substrate; Coating is on oneside Haze of PC substrate with primer was 0.38% before application ofcoating

Table 3 shows that the combination of two aged coating solutions(Examples 9 and 10) yielded a coating with haze of less than 1%. Thisfinding applied to both acid-stabilized colloidal silica (Example 9) andammonium-stabilized colloidal silica (Example 10). It is noted thatalthough two weeks of aging were used in the example, shorter agingtimes are believed possible, even when aging at room temperature andwhile attaining a haze of less than 1%. For example, aging of greaterthan or equal to 24 hours, specifically, greater than or equal to 48hours, and more specifically, greater than or equal to 1 week, withagitation (e.g., stirring). Times may be further decreased with heatingof the mixtures.

Examples 11-14 Taber Abrasion Resistance

One of the problems encountered with the addition of ITO to the siliconehard coat was the increase in Taber delta haze as compared to the samesilicone hard coat without the ITO.

Polycarbonate (PC) substrates with primer were prepared as in Example 4.For Example 11, a colloidal silica coating mixture (AS4700) was appliedto the polycarbonate substrate with primer, allowed to stand for 15minutes at room temperature, and cured in oven at 125° C. for 1 hour.For Examples 12-14 an ITO coating mixture was prepared as in Example 4,except that, in these examples, the ITO amount was such that, after theITO coating mixture was combined with the colloidal silica coatingmixture in a 1:2 weight ratio, the loading of ITO in the resulting curedcoating was the same as for Example 3b. The ITO coating mixture was agedat room temperature (20° C.) with stiffing for 14 days before beingcombined with the colloidal silica coating mixture to form a combinedmixture. The combined mixture was applied to the polycarbonate substratewith the primer, allowed to stand for 15 minutes at room temperature,and cured in an oven at 125° C. for 1 hour.

TABLE 4 Taber Abrasion Resistance Weight Ratio of Mixtures ITO CoatingTaber delta Ex. ITO:CS wt % TBAA* Mixture** haze (%)*** 11 0:1 0.4 — 4.112 1:2 0.4 Unextracted 7.6 13 1:2 0.4 Extracted 4.3 14 1:2 0.6Unextracted 4.0 *Based upon total weight of solids in the cured coating.**Treatment of the ITO coating mixture before it is combined withcolloidal silica coating mixture (namely AS4700); not believed necessaryif the original ITO dispersion is sufficiently pure. ***Taber Protocol:ASTM D1044-08, CF-10F Wheels, 500 g Load, 500 Cycles

Table 4, Example 12, illustrates that a coating formed from the 1:2weight ratio mixture has much higher Taber delta haze (7.6%) than acoating formed from pure colloidal silica coating mixture (4.1%, Example11) when both coatings contain 0.4 wt % of TBAA and when no steps aretaken to purify the ITO coating mixture. Table 4 indicates two ways toachieve Taber comparable to pure colloidal silica coating mixture: (i)at least partially purify (e.g., by extraction) the ITO dispersionbefore blending with the colloidal silica coating mixture (Example 13);and/or increase the TBAA loading, e.g., to 0.6% (Example 14).

For Example 13, 25 g of the ITO coating mixture was shaken with 50 g ofwater. After settling for several minutes, the aqueous phase wasdecanted from the residual blue slurry, and the extraction was repeatedtwice using 25 g of water each time. The residual blue slurry was thenre-dispersed in sufficient 1-methoxy-2-propanol to give a blue solutionwith the same solids level of the original ITO coating mixture. One partof this ITO coating mixture was combined with 2 parts of the colloidalsilica coating mixture and adjusted to contain 0.4% TBAA catalyst. Thecombined mixture was applied to the polycarbonate substrate with theprimer and cured for 1 hour at 125° C. The Taber delta haze was 4.3%,which is comparable to the Taber delta haze for Example 11.

For Example 14, one part of the unextracted ITO coating mixture wasblended with 2 parts of colloidal silica coating mixture and adjusted tocontain 0.6% TBAA catalyst. The combined mixture was applied to thepolycarbonate substrate with the primer and cured for 1 hour at 125° C.The Taber delta haze was 4.0%, which is comparable to the Taber deltahaze for Example 11.

Examples 13 and 14 show that an inhibition of the cure, possibly due toimpurities in the ITO dispersion, can be remedied by purification of theITO coating mixture or by adding more cure catalyst. Alternatives toextraction would be to purify the ITO dispersion or the ITO coatingmixture (e.g., by ion exchange) and/or to produce the ITO dispersionwith adequate purity at the outset.

Employment of multiple additives in multiple different locations canenable tuning of the transmission spectrum of an article. The use ofdifferent locations also enables the use of incompatible materials(i.e., if they were co-located). The ability to distribute additivesamong multiple locations also helps overcome additive concentrationlimitations, e.g., related to haze generation (e.g., due toagglomeration of additive particles) and/or to processing requirements(e.g., for injection molding). It also enables use of a common substrateresin (with some baseline additive(s)) for multiple applications,combined with selective use of additional additives in glazing elementsother than the substrate, to efficiently accommodate a range ofapplications with a range of spectral requirements.

In an embodiment, a method for making an infrared radiation absorbingcoating comprises: forming an ITO coating mixture comprising ITO and afirst coating matrix, wherein the first coating matrix comprises thepartial condensate of a silanol of the formula R_(n)Si(OH)_(4-n), wheren equals 1 or 2, and wherein R is selected from a C₁₋₃ alkyl radical, avinyl radical, a 3,3,3-trifluoropropyl radical, a gamma-glycidoxypropylradical, and a gamma-methacryloxypropyl radical, wherein the ITO coatingmixture is free of colloidal silica; forming a colloidal silica coatingmixture comprising colloidal silica and a second coating matrix, whereinthe second coating matrix comprises the partial condensate of a silanolof the formula R_(n)Si(OH)_(4-n), where n equals 1 or 2, and wherein Ris selected from an alkyl radical of 1 to 3 inclusive carbon atoms, avinyl radical, a 3,3,3-trifluoropropyl radical, a gamma-glycidoxypropylradical, and a gamma-methacryloxypropyl radical; and mixing the ITOcoating mixture with the colloidal silica coating mixture to form acombined mixture. The combined mixture does not comprise a precipitatevisible to the unaided eye after 2 weeks without stiffing.

In an embodiment, a silicone coating composition comprises: a coatingmatrix, comprising the partial condensate of a silanol of the formulaR_(n)Si(OH)_(4-n), where n equals 1 or 2, and wherein R is selected froma C₁₋₃ alkyl radical, a vinyl radical, a 3,3,3-trifluoropropyl radical,a gamma-glycidoxypropyl radical, and a gamma-methacryloxypropyl radical;colloidal silica; and ITO having a mean particle size of less than orequal to 60 nm as determined by dynamic light scattering.

In another embodiment, a silicone coating composition comprises: acoating matrix comprising the partial condensate of a silanol of theformula R_(n)Si(OH)_(4-n), where n equals 1 or 2, and wherein R isselected from a C₁₋₃ alkyl radical, a vinyl radical, a3,3,3-trifluoropropyl radical, a gamma-glycidoxypropyl radical, and agamma-methacryloxypropyl radical; ITO having a mean particle size ofless than or equal to 60 nm as determined by dynamic light scattering;and wherein the silicone coating is free of CS.

In another embodiment, a coated glazing comprises: a plastic substrate;and a cured silicone coating on the substrate. The cured siliconecoating was formed from a composition consisting essentially of acoating matrix, comprising the partial condensate of a silanol of theformula R_(n)Si(OH)_(4-n), where n equals 1 or 2, and wherein R isselected from an alkyl radical of 1 to 3 inclusive carbon atoms, a vinylradical, a 3,3,3-trifluoropropyl radical, a gamma-glycidoxypropylradical, and a gamma-methacryloxypropyl radical; colloidal silica; ITOhaving a mean particle size of less than or equal to 60 nm as determinedby dynamic light scattering; and optionally an additive selected fromthe group consisting of a UV absorber, a surfactant, a plasticizer, IRabsorber, cure catalyst, colorant, antistat, antibacterial a flowadditive, an anti-oxidant, a dispersant, compatibilizer, and acombination comprising at least one of the foregoing additives. Thecoated glazing has a haze of less than or equal to 3% as measured inaccordance with ASTM D1003-11, procedure A with CIE standard illuminantC.

In the various embodiments: (i) forming the ITO coating mixture furthercomprises aging the ITO coating mixture; and/or (ii) no polymericdispersant is added to the ITO coating mixture, the colloidal silicacoating mixture, or the combined mixture; and/or (iii) the first coatingmatrix and the second coating matrix are the same; and/or (iv) thecoating composition comprises less than or equal to 0.05 parts by masspolymeric dispersant with respect to 1 part by mass ITO; and/or (v) thecoating composition comprises 0 parts by mass polymeric dispersant;and/or (vi) wherein greater than or equal to 90% of ITO particles have adiameter of less than 61 nm; and/or (vii) further comprising UVabsorbing additives; and/or (viii) further comprising a quaternaryammonium salt of a carboxylic acid; and/or (ix) wherein the ITO coatingmixture comprises the quaternary ammonium salt of the carboxylic acid;and/or (x) further comprising a cure catalyst selected fromtetra-n-butylammonium acetate (TBAA), tetra-n-butylammonium formate,tetra-n-butylammonium benzoate, tetra-n-butylammonium-2-ethylhexanoate,tetra-n-butylammonium-p-ethylbenzoate, tetra-n-butylammonium propionate,and combinations comprising at least one of the foregoing; and/or (xi)wherein the coated glazing has a T_(vis) of greater than or equal to 70%and a T_(ts) of less than or equal to 60%; and/or (xii) wherein theplastic substrate comprises a material selected from polycarbonateresin, acrylic polymers, polyacrylate, polyester, polysulfone resins,and combinations comprising at least one of the foregoing; and/or (xiii)wherein the haze is less than or equal to 2%; and/or (xiv) wherein thehaze is less than or equal to 1%; and/or (xv) further comprising a UVprotective coating on both sides of the plastic substrate; and/or (xvi)further comprising a UV protective coating on one side of the plasticsubstrate and an IR coating on an opposite side of the plasticsubstrate; and/or (xvii) wherein the composition comprises an amount ofpolymeric dispersant such that if the ITO were mixed directly with thecolloidal silica coating mixture to form a sample mixture having thesame amount of polymeric dispersant as the combined mixture, visibleprecipitation occurs in the sample mixture in less than or equal to oneweek with no agitation.

In general, the invention may alternately comprise, consist of, orconsist essentially of, any appropriate components herein disclosed. Theinvention may additionally, or alternatively, be formulated so as to bedevoid, or be substantially free, of any components, materials,ingredients, adjuvants or species used in the prior art compositions orthat are otherwise not necessary to the achievement of the functionand/or objectives of the present invention.

All ranges disclosed herein directed to the same component or propertyare inclusive of the endpoints, and the endpoints are independentlycombinable with each other (e.g., ranges of “up to 25 wt %, or, morespecifically, 5 wt % to 20 wt %,” is inclusive of the endpoints and allintermediate values of the ranges of “5 wt % to 25 wt %,” such as 10 wt% to 23 wt %, etc.). “Combination” is inclusive of blends, mixtures,alloys, reaction products, and the like. Furthermore, the terms “first,”“second,” and the like, herein do not denote any order, quantity, orimportance, but rather are used to distinguish one element from another.The terms “front”, “back”, “bottom”, and/or “top” are used herein,unless otherwise noted, merely for convenience of description, and arenot limited to any one position or spatial orientation. The terms “a”and “an” and “the” herein do not denote a limitation of quantity, andare to be construed to cover both the singular and the plural, unlessotherwise indicated herein or clearly contradicted by context. Thesuffix “(s)” as used herein is intended to include both the singular andthe plural of the term that it modifies, thereby including one or moreof that term (e.g., the film(s) includes one or more films). Referencethroughout the specification to “one embodiment”, “another embodiment”,“an embodiment”, and so forth, means that a particular element (e.g.,feature, structure, and/or characteristic) described in connection withthe embodiment is included in at least one embodiment described herein,and may or may not be present in other embodiments. In addition, it isto be understood that the described elements may be combined in anysuitable manner in the various embodiments.

All cited patents, patent applications, and other references areincorporated herein by reference in their entirety. However, if a termin the present application contradicts or conflicts with a term in theincorporated reference, the term from the present application takesprecedence over the conflicting term from the incorporated reference.

While particular embodiments have been described, alternatives,modifications, variations, improvements, and substantial equivalentsthat are or may be presently unforeseen may arise to Applicants orothers skilled in the art. Accordingly, the appended claims as filed andas they may be amended are intended to embrace all such alternatives,modifications variations, improvements, and substantial equivalents.

I/We claim:
 1. A silicone coating composition, comprising: a coating matrix comprising a partial condensate of a silanol of the formula R_(n)Si(OH)_(4-n), where n equals 1 or 2, and wherein R is selected from a C₁₋₃ alkyl radical, a vinyl radical, a 3,3,3-trifluoropropyl radical, a gamma-glycidoxypropyl radical, and a gamma-methacryloxypropyl radical; and ITO having a mean particle size of less than or equal to 60 nm as determined by dynamic light scattering; and wherein the silicone coating composition is free of colloidal silica.
 2. The silicone coating composition of claim 1, wherein the coating composition comprises less than or equal to 0.05 parts by mass polymeric dispersant with respect to 1 part by mass ITO.
 3. The silicone coating composition of claim 1, wherein the coating composition comprises 0 parts by mass polymeric dispersant.
 4. The silicone coating composition of claim 1, wherein the ITO has a mean particle size of less than or equal to 45 nm as determined by dynamic light scattering.
 5. The silicone coating composition of claim 1, wherein greater than or equal to 90% of ITO particles have a diameter of less than 61 nm.
 6. The silicone coating composition of claim 1, wherein the ITO comprises particles and wherein greater than or equal to 95% of ITO particles have a diameter of less than or equal to 71 nm.
 7. The silicone coating composition of claim 1, further comprising a quaternary ammonium salt of a carboxylic acid.
 8. The silicone coating composition of claim 1, further comprising a cure catalyst selected from tetra-n-butylammonium acetate (TBAA), tetra-n-butylammonium formate, tetra-n-butylammonium benzoate, tetra-n-butylammonium-2-ethylhexanoate, tetra-n-butylammonium-p-ethylbenzoate, tetra-n-butylammonium propionate, and combinations comprising at least one of the foregoing.
 9. The silicone coating composition of claim 1, further comprising a cure catalyst is present in an amount of less than or equal to 2 wt % based upon a total weight of solids in the composition.
 10. The silicone coating composition of claim 1, wherein the silanol comprises greater than or equal to 70 wt % of CH₃Si(OH)₃.
 11. The silicone coating composition of claim 1, wherein the composition comprises a UV absorber.
 12. A coated glazing, comprising: a plastic substrate; and a cured silicone coating on the substrate, wherein the cured silicone coating was formed from the silicone coating composition of claim
 1. 13. The coated glazing of claim 12, wherein the coated glazing has a T_(vis) of greater than or equal to 70% and a T_(ts) of less than or equal to 60%.
 14. The coated glazing of claim 12, wherein the plastic substrate comprises a material selected from polycarbonate resin, acrylic polymers, polyacrylate, polyester, polysulfone resins, and combinations comprising at least one of the foregoing.
 15. The coated glazing of claim 12, further comprising a UV protective coating on both sides of the plastic substrate.
 16. The coated glazing of claim 12, further comprising a UV protective coating on one side of the plastic substrate and an IR coating on an opposite side of the plastic substrate. 